Paul Klee was also an experimental technician. He tested different supports and paint formulas, examined the effects of pigments, binders, grounds, and coatings, and meticulously recorded the materials in his handwritten catalogue raisonné. In addition, he employed his specific method of assemblage using backing boards, colored borders, and inscriptions. He displayed particular inventiveness in multiplying his works. For example, he developed oil painting, which he used to reproduce drawings, and he used scissors to create two or even more images from one. Numerous and varied compositions of Klee's cut-up paintings can be found. He also divided "Forest Bird" horizontally with scissors. This cut created two different compositions: a plant image titled "Poison Berries" (location unknown) and the lower part of the painting, "Forest Bird," exhibited here.